This invention relates to antibiotics of the cephalosporin class. In particular, it relates to 3,7-disubstituted cephalosporins wherein the 3-position substituent is either the 1-methyl-1H-tetrazolyl-5-thiomethyl group or the 5-methyl-1,3,4-thiadiazolyl-2-thiomethyl group and the 7-position substituent is the D-4-(or -3-)hydroxyphenylglycylamido group.
In U.S. Pat. No. 3,641,021, issued Feb. 8, 1972, to Ryan, certain 7-mandelamido and 7-phenylglycylamido substituted cephalosporins having the above-described heterocyclic thiomethyl substituents are described as possessing stability to liver enzymes and cephalosporinase enzymes. Included among a number of substituents which may be present on the phenyl ring of the mandelamido or phenylglycylamido side chain is the hydroxy group. Ryan does not describe with any particularity any specific hydroxyphenylglycylamido substituted cephalosporin in contrast with the description provided for the phenylglycylamido and mandelamido 7-position side chains wherein the phenyl rings are unsubstituted.